1. Technological Field
The present invention relates to a filter device and similar devices.
2. Background Technology
In, for example, a pulsation detection device for detecting a pulsation signal originating from pulsation in a test subject, a filtering process is performed by a filter device as a pre-process for detecting the pulsation signal. A signal inputted into the filter device is a pulse wave signal including, e.g., a pulsation signal, which is a steady component; and a body motion component originating from disturbance noise and the body motion of the test subject, which is a non-steady component.
A technology for filtering and thereby removing the noise component included in the pulse wave signal is described in, e.g., Patent Citation 1. In the technique described in Patent Citation 1, a band pass filter that passes a signal having a frequency near a frequency representing the pulse at that point in time is selected from a plurality of band pass filters.
Japanese Laid-open Patent Publication No. 2007-54471 (Patent Document 1) is an example of the related art.